Explanation

Muhammad Bin Qasim was the nephew of Hajjaj bin Yusuf, the Umayyad governor of Iraq.

Muhammad Bin Qasim was a close relative of Hajjaj bin Yousuf.

He was the son-in-law of Hajjaj bin Yousuf

Because of him, he was appointed the governor of Persia.

Hajjaj ibn Yusuf was the governor of the Umayyad Caliphate from 692–694.

Additional information 

Muhammad ibn Qasim led the Muslim conquest of Sindh.

From Raja Dahir in the battle of Aror.

He was the first Muslim to have successfully captured Hindu territories

And initiated the early Islamic India in 712 AD.